In the following, a programming station refers to computer equipment, particularly a PC type personal computer, that can be connected to an automation equipment. In the following, automation equipment refers to a programmable logic controller, an instrumentation/control station, a numerical control or other equipment that can contain and execute an application program controlling an automation application. For example, this automation application may be in the domain of industrial process automation, building automation or instrumentation/control of electrical distribution networks.
This type of automation equipment is composed of a central unit and one or several input-output modules connected to sensors and preactuators of the automation application to be controlled.
The central unit comprises at least one processor, a non-volatile memory, usually not modifiable (ROM) or modifiable (EEPROM) containing the manufacturer's program also called the proprietary operating system, expressed in a language specific to the manufacturer of the automation equipment, a RAM memory and an input-output manager communicating together through a back plane bus. A first area of the RAM memory (also called the volatile memory) contains the user's program, and a second area contains the data, and particularly images of the states of input-output modules and constants related to the user's program.
The user's program, also called the application program, monitors or controls an automation application by means of inputs-outputs controlled by this application program. The designer creates this program and it is written in one or several graphic automation languages particularly including Ladder Diagrams called Ladder language in the following, Sequential Function Charts called SFC language in the following, Function Block Descriptions called FBD language in the following, or in IL (Instruction List) or ST (Structured Text) type automation text languages. These automation languages are preferably conform with standard IEC 1131-3 to facilitate programming by an automation designer who is not necessarily familiar with computer languages. These languages can be used on programming stations that may or may not be connected to an automation equipment to be programmed.
At the moment, application programs created using graphic automation languages conform with standard IEC 1131-3 cannot be exchanged between automation equipment made by different manufacturers with manufacturer programs based on different manufacturer languages. After the designer of an automatic control has produced the application program in one of the standard languages, the programming station on which the designer is working translates this program into the specific language of the manufacturer of the automation equipment on which the application program was developed, since there is no standard exchange format.